class CreateAmountChanges < ActiveRecord::Migration
  def self.up
    create_table :amount_changes do |t|
      t.references :amount
      t.references :operation

      t.decimal :delta, :default => 0
      t.decimal :old_value, :default => 0
    end
  end

  def self.down
    drop_table :amount_changes
  end
end
